The present invention relates to vane pumps.
Japanese Patent 3631264 discloses a vane pump which includes a rotor provided with vanes extending radially of the rotor, wherein each vane is mounted in a slot, wherein each slot extends radially of the rotor. The vane pump includes first and second arc-shaped recesses formed to face an annular region in which a proximal end portion of each slot is located. The first arc-shaped recess corresponds to a suction region in which pumping chambers expand and suck working fluid along with rotation of the rotor. The first arc-shaped recess is supplied with a suction-side hydraulic pressure. The second arc-shaped recess corresponds to a discharge region in which the pumping chambers contract and discharge working fluid along with rotation of the rotor. The second arc-shaped recess is supplied with a discharge-side hydraulic pressure.